Known devices may be helpful in providing in-vivo sensing, such as imaging or pH sensing. Autonomous in-vivo sensing devices, such as swallowable or ingestible capsules or other devices may move through a body lumen, sensing as they move along. An autonomous in-vivo sensing device such as an imaging device may include, for example, an imager for obtaining images from inside a body cavity or lumen, such as the gastrointestinal (GI) tract. The imager may, for example, be associated with an optical system, and optionally a transmitter and an antenna. Some of these devices use a wireless connection to transmit image data.